Generic image carriers are used, in particular for medical purposes, in the field of computer radiography (CR). For this, X-ray images are recorded in a storage phosphor layer by storing the X-radiation passing through an object, for example a patient, as a latent image in the storage phosphor layer. In order to read the stored X-ray information the storage phosphor layer is illuminated with stimulation light, whereby the layer is excited to emit light, which is captured by an optical detector and converted into electrical signals. The electrical signals may be processed further as necessary and displayed on a monitor or output on a corresponding output device, such as for example a printer. After an erasure procedure, in which any remaining X-ray information is completely eliminated from the storage phosphor layer, the storage phosphor layer is available for recording further X-ray photographs.
Apart from a storage phosphor layer for storing X-ray information, image carriers according to the prior art include for example an integrated electronic circuit with a memory, in which information associated with the image carrier and/or an X-ray photograph can be stored. This information is used in a subsequent processing of the image carrier in a processing device, for example a read-out device for reading the storage phosphor layer, and/or in a processing of the image data generated in the read-out.
In order to store the data necessary for the processing in the memory of the integrated circuit a great deal of storage space is required, particularly when different types of processing are involved. Since the storage capacity of the electronic memories that are conventionally used is limited, often not all the required data can be contained on the image carrier.